This invention relates to a solar energy collector to be normally fabricated from sheet metal and secured to an object to provide increased effective surface area to the object for enhanced absorption or collection of solar energy impinging on the surface thereof.
The invention relates more particularly to a structure which is related to the structure disclosed in the above-referenced parent application. The related structure is intended as a heat transfer fin structure which not only has unexpectedly high heat transfer efficiency but also has relatively high peripheral stability or resistance to physical deformations, as compared with other similar structures, as is discussed in detail in the above-referenced application. However, it has been found that by modifying the the structure disclosed in the above-referenced parent application, it will operate as an efficient solar energy collector. As can readily be seen from FIG. 4 of the parent application, solar energy impinging upon the structure from a radial direction will only "see" the edge of the spiral fin and therefore will "see" large gaps between these spirals. This clearly will result in less than optimum solar energy collection efficiency. In this respect, it is noted that the above-referenced related application purported to teach a solar energy collector but has now been found, with some modification, to be a highly efficient solar energy collector.
The usual construction employed for a solar energy collector is a combination of a darkened sheet of material presenting a relatively large surface to the sun; and a conduit in heat exchange relationship with that material. Solar energy is absorbed by the large darkened surface which is heated thereby and a fluid flowing through the conduit acts to remove the heat from the surface for use elsewhere. Many different arrangements which substantially have this basic structure have been proposed. U.S. Pat. No. 2,594,232, to Stockstill, shows several possible arrangements of this type which are used to collect solar energy and utilize it to heat a liquid.
Further discussion of these "flat plate" type of collectors, as well as other types of collectors, can be found in "Solar Heating and Cooling," a text by Kreider and Kreith, (Hemisphere Publishing Corp., revised first edition, 1977), especially Chapter 3, which text is incorporated herein by reference.